1. Field of the Invention
The present invention relates to an original (for example, a mold to be used in an imprint apparatus or a mask to be used in an exposure apparatus) and an article manufacturing method using the same.
2. Description of the Related Art
As the demand for microfabrication of semiconductor devices increases, not only is there a conventional photolithography technique, but there is also a microfabrication technique in which a mold (original) and an uncured resin on a substrate are pressed against each other to thereby form a resin pattern, which corresponds to a fine concave and convex pattern formed on the mold, on the substrate. This technique is also referred to as an “imprint technique”, by which a fine structure on the order of a few nanometers can be formed on the substrate. One example of imprint techniques includes a photo-curing method. Firstly, the photo-curing method applies an ultraviolet curable resin (imprint resin, photocurable resin) to the shot area (imprint area) on the substrate. Next, the resin (uncured resin) and a mold are pressed against each other. After the ultraviolet curable resin is irradiated with ultraviolet light for curing, the cured resin is released from the mold, whereby a resin pattern is formed on the substrate.
As imprint apparatus employing the aforementioned technology corrects the shape of a mold using a shape correction mechanism depending on the shape of a pattern on a substrate. At this time, shape correction includes not only simple magnification corrections but also corrections in which the shape of a mold is deformed into another shape such as a parallelogram or a trapezoid. In general, the shape correction mechanisms are installed in plural locations on the outer circumference portion of a mold. Each of the shape correction mechanisms imparts an external force to a mold from the outer circumference portion to thereby cause the mold itself to be deformed, so that the pattern shape formed on the mold is corrected. The pattern shape affects the superposition accuracy of the patterns. In particular, for the correction of the pattern shape using a shape correction mechanism, a highly accurate correction on the order of less than a few nanometers is required in order to accommodate the recent trend toward pattern micronization. As a device for correcting the shape of a pattern, such as a shape correction mechanism, Japanese Patent Laid-Open No. 2008-504141 discloses a device that applies a compressive force to the mold-side surface to thereby perform magnification correction. The device is constituted by an actuator, a link mechanism, and the like. The devices are installed in plural locations so as to enclose the outer circumference portion of a mold.
However, in the device disclosed in Japanese Patent Laid-Open No. 2008-504141, when a force is applied to a mold from the outer circumference portion thereof (for example, when a pattern is corrected into a trapezoidal shape), a large correction error may occur. Here, assume the case where a mold is formed of quartz having a positive Poisson's ratio. In this context, the device disclosed in Japanese Patent Laid-Open No. 2008-504141 applies a compressive force to one base for shortening the length thereof and a tensile force to the other base for extending the length thereof. In this case, the shortened base of the mold is bent inward and the extended base thereof is bent outward due to the effect of Poisson's ratio. Thus, a correction error newly occurs due to the shape correction of a pattern into a trapezoidal shape.